Assessing the well being of fetus is a very important clinical practice in pregnancy care. Currently, the most prevalent ways for doctors to assess fetal well-being are the analysis of fetal heart rate using a cardio-tocograph (CTG) and the assessment of maternal and fetal blood vessel flows using ultrasound Doppler. Ultrasound Doppler waveform analysis of specific blood flows of fetus and mother is part of established medical practice, and a standard recommendation in various clinical guidelines for the diagnosis and assessment of high-risk pregnancies (type-2 diabetes, hypertension or pre-eclampsia in mother and IUGR—intra-uterine growth restriction of fetus). One of the main aims of routine antenatal care is to identify the “at risk” fetus in order to clinically intervene, thereby reducing the incidence of perinatal morbidity and mortality. Some of the vessels useful in the assessment of fetal well-being are: the umbilical artery, the middle cerebral artery, the ductus venosus, and the (left and right) uterine arteries and umbilical veins.
Ultrasound scanners have become indispensible in the monitoring of pregnancies worldwide. They currently provide the best option to monitor the growth and development of the fetus. Duplex ultrasound scanners provide ultrasound pulsed wave Doppler in addition to the regular scan. Color and power Doppler are newer additions to the range of scanners that provide for vascular imaging. Color Doppler, in particular, is commonly provided, resulting in what is often called a “triplex” scanner. In a 2D color flow mapping, the spatial image of the vessels is overlaid with the flow image such that the ultrasound reflection is represented in gray scale and the flow velocity information is rendered in color.
Doppler exams typically require a great degree of skill to obtain a clinically useful measurement. For example, correct orientation of the probe with respect to the vessel is essential to ensure that the beam-flow angle is less than 60 degrees. Errors in measurements are amplified when angles of greater than 60 degrees are used in the determination of velocities. The standard workflow on a clinical ultrasound scanner allows a sonographer to determine the orientation of the probe with respect to the vessel using a standard B-mode and Color Flow display. The spectral Doppler measurements are then obtained thus ensuring that the measured velocities are correct.
Also, currently the sample volumes are manually set by radiologists which requires skill.
The use of ultrasound in vascular applications to perform Doppler velocimetry requires availability of skilled personnel.
Duplex ultrasound scanners are used to measure the rate of flow in blood vessels and to produce spectrograms representative of the blood flow. Measurements can be made based on the spectrogram to yield Doppler indices used by the physician in rendering a medical diagnosis. The blood vessel by which the diagnosis is to be made is, via the display, identified anatomically by its name.
U.S. Patent Application 2011/0034807 to Yoo et al. discloses an ultrasound system for automatically labeling vessels in the sense of marking an imaging-wise segmented vessel with a number or color to differentiate it from another segmented vessel.